File 0001-fs-btrfs-Zero-file-data-not-backed-by-extents.patch of Package grub2.38572

From f903b9a9adb64e733e581771d2a24efae7fbe529 Mon Sep 17 00:00:00 2001
From: Fabian Vogt <fvogt@suse.de>
Date: Thu, 5 Oct 2023 11:02:25 +0200
Subject: [PATCH] fs/btrfs: Zero file data not backed by extents

Implicit holes in file data need to be zeroed explicitly, instead of
just leaving the data in the buffer uninitialized.

This led to kernels randomly failing to boot in "fun" ways when loaded
from btrfs with the no_holes feature enabled, because large blocks of
zeros in the kernel file contained random data instead.

Signed-off-by: Fabian Vogt <fvogt@suse.de>
---
 grub-core/fs/btrfs.c | 2 ++
 1 file changed, 2 insertions(+)

--- a/grub-core/fs/btrfs.c
+++ b/grub-core/fs/btrfs.c
@@ -1665,6 +1665,8 @@
 	      csize = grub_le_to_cpu64(key_out.offset) - pos;
 	      if (csize > len)
 		      csize = len;
+
+	      grub_memset (buf, 0, csize);
 	      buf += csize;
 	      pos += csize;
 	      len -= csize;